Muffler



Nov. 1, 1960 c. H. PAuLsr-:N

MUFFLER Filed Jan. 5o, 195a` Y W i ,A. Y

@nalllllllllll l FIG.4

INVENTOR C H PAULSEN ATTORNEY United States Patent O M MUFFLER Chris H. Paulsen, 371 Wisconsin SW., Huron, S. Dak.

Filed `lan. 30, 1958, Ser. No. 712,101

3 Claims. (Cl. 181-42) This invention relates to sound, the transmission thereof, and the manner of treating sound waves in order to absorb and dampen the same thereby to greatly reduce or muifle if not eliminate noise.

The invention relates more particularly to the muiiiing of the sound of explosions in an internal combustion engine and especially those used on motor vehicles where the eflciency of the motor is reduced by back pressure of the muiflers heretofore in use.

In internal combustion engines the exhaust contains moisture, unburned fuel in both gaseous and liquid form, and oil deposits which are destructive of the mufer. Muiilers heretofore in use have not been satisfactory because they have included bailies and other obstructions which caused the accumulation of back pressure with increased heating and deterioration resulting in over-heating of the engine, improper firing of the gas mixture, and generally unsatisfactory operation.

It is an object of the invention to provide a relatively simple inexpensive and eflicient muffler for reducing sound produced by the explosions within an internal combustion engine which mufer will be devoid of baffles and other obstructions in the path of travel of the exhaust from such engine and therefore will afford unrestricted flow therethrough.

Another object of the invention is to provide a muffler both lined with and having a core of sound absorptive material within and about Which the sound may travel and with discharge outlets through which condensate can exude without the discharge of appreciable sound.

Another object of the invention is to provide a mufer with the fewest number of parts including a shell, a lining of pre-formed sound absorbing material within said shell and a central sound and transverse wave interceptor and absorption core to accomplish maximum sound reduction.

Other objects and advantages of the invention will be apparent from the following description taken in conjunction with the accompanying drawing wherein:

Fig. 1 is a perspective of a muffler in accordance with the present invention;

Fig. 2, a section on the line 2 2 of Fig. l;

Fig. 3, a section on the line 3 3 of Fig. l; and

Fig. 4, a fragmentary longitudinal section of a modified form of the invention.

Briefly stated, the muflier of the present invention may be either the modification of the exhaust pipe or the application to such pipe of a separate casing with an inlet and an outlet, and in either case lined with sound absorbing material adapted to be engaged by the sound waves traveling back and forth across the passage in its path from the engine to the atmosphere. The sound absorbing material may be in the form of a preformed lining and may have one or more sound wave interceptor cores. In either of the above systems there is unobstructed ow through the exhaust system without back pressure.

2,958,388 Patented Nov. 1, 1960 ICC With continued reference to the drawing the muiiler comprises a shell or casing 10 of metal or other desirable material capable of withstanding the heat and the use to which the muiiler is subjected. The shell or casing 10 has an inlet 11 at one end and an outlet 12 at its opposite end both of reduced size.

In view of the fact that the exhaust from an internal combustion engine contains condensate the inlet 11 and outlet 12 are provided respectively with condensate discharge cups or tubes 13 and 14 respectively with discharge openings 15 and 16 in their bottoms. The discharge tubes 13 and 14 are filled with material 17 having heat insulating and sound absorbing qualities of well known character such as fiberglass or the like.

The interior of the shell or casing 10 forms an expansion chamber '18 and in order to contribute to the low height of the automobile the shell or casing may be of flattened or oval shape and have its major transverse axis disposed horizontally although the disposition and shape may be modified as desired.

In order to absorb and dampen sound waves within the shell or casing 10 a lining 19 is provided of maximum heat insulating and sound absorbing material, and for ease of manufacture and durability this lining is preferably preformed with the interior surface thereof fully exposed within the chamber so that it functions similarly to a ceiling or wall having a sound deadening surface.

It will be apparent that there is provided an expansion chamber of substantial length and cross section in which the exhaust is received and is permitted to pass through substantially unobstructed there being no back pressure creating baies to extract heat from the exhaust and sound wave will be substantially absorbed and dampened.

In order to intercept sound waves traveling back and forth across the chamber within the muffler an elongated core 20 may be provided and such core may be supported or suspended in any desired manner, one simple and satisfactory way being by means of horizontal and vertically disposed cross pins or Wires 21 and 22 through the end portions of the core and extending through the pre-formed sound absorbing lining and welded or otherwise secured to the shell or casing 10.

Instead of the oval casing disclosed in Figs. 1 to 3 the muffling may be accomplished by means of an axhaust pipe 23 provided with a heat insulating, sound absorbing lining 24 which may be pre-formed. The lining 19, core 20, and lining 24 may be made from fiberglass.

The exhaust pipe 23 comprises a metal tube somewhat larger in diameter than the manifold exhaust and may be attached to the same by spacer 25 and band 26 in a conventional manner. The pre-formed sound absorbing lining 24 may have a central opening extending the full length of the pipe substantially the same diameter as the inside diameter of the manifold exhaust so that no obstructions will be interposed in the path of the exhaust gases as the sound is absorbed by the lining.

It will be apparent that a simple inexpensive muier is provided having certain advantages without accompanying undesirable characteristics or disadvantages as well as a mufer which will operate elliciently to perform the function for which it was designed.

It will be obvious to those skilled in the art that various changes may be made in the invention without departing from the spirit and scope thereof and therefore the invention is not limited by that which is illustrated in the drawing and described in the specification, but only as indicated in the accompanying claims.

What is claimed is:

1. A muffler comprising an elongated casing having open ends, said casing havingv a preformed sound-attenuat'ing lining in intimate contact therewith, a core off like preformed sound-attenuating material within and extending a major portion of the length of said casingy and supporting meansr extending from said core and anchored in said lining. Y

2. A muflier as set forth in clairn 1 wherein said sup porting means is crossed wires extending through said core and anchored in said lining.

3^. A muffler as set forth in claim l and including an inlet tube extending from one, end of said casing, an outlet tube from the opposite. endof said casing, a discharge cup extendingl downwardly from said inlet tube and com- 15 2,824,619

municating therewith, a discharge cup extending downwardly from said outlet tube and communicating therewith, said discharge tubes having discharge openings formed in their bottoms, said discharge tubes being lled 5 with insulating and sound absorbing material.

References Cited in the le of this patent UNITED STATES PATENTS 10 1,844,104. Schnell Feb. 9, 1932 2,065,343 Moore et al. Dec. 22, 1936 2,241,768 Deremer May 13, 1941 2,600,236 Gibel June 10, 1952 2,613,758 Cullum Oct. 14, 1952 Bremer et al. Feb. 25, 1958 

